Php regular function 2preg_match_all-php tutorial

Php regular function 2 preg_match_all ???? Let's continue with the perl-style regular function preg_match_all .???? Function prototype :? & Lt ;? Php & gt; preg_match_all ($ pattern, $ subject, array & amp; $ matchesnull, $ flagsnull, $ offset php regular function 2 preg_match_all

? ? ? ? Let's continue with the perl-style regular function preg_match_all.

? ? ? ? Function prototype:

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 preg_match_all ($pattern, $subject, array &$matches = null, $flags = null, $offset = null)
 

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? ? ? ? Parameter: Identical to preg_match.

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? ? ? ? Function: similar to preg_match, preg_match_all matches $ pattern in the $ subject string. Unlike preg_match, preg_match_all does not stop searching for the first matching result, search until the end of $ subject.

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? ? ? ? Return value: according to the function, we can see that not only 0 or 1 is returned, preg_match_all searches for the entire $ subject until the end, and returns a few matching results. Let's look at an example with matching results.

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 $url = 'http://www.sina.com.cn/abc/de/fg.php?fff.html?id=1';$matches = array();$pattern = '/(\.){1}[^.|?]+(\?){1}/i';$count = preg_match_all($pattern, $url, $matches);var_dump($count);var_dump($matches);
 

? Output

int 2array (size=3)  0 =>     array (size=2)      0 => string '.php?' (length=5)      1 => string '.html?' (length=6)  1 =>     array (size=2)      0 => string '.' (length=1)      1 => string '.' (length=1)  2 =>     array (size=2)      0 => string '?' (length=1)      1 => string '?' (length=1)

? This example matches two results, which are http://www.sina.com.cn/abc/de/fg. Php?Fff. Html?Id = 1 the two red parts of the string. You will find that the elements in $ matches are also array types, $ matches [0] stores matching results, and $ matches [1] stores matching results of sub-regular 1, $ matches [2] stores the result of regular 2 matching. It may not be intuitive.

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The Black Arrow is $ pattern regular match, and the Green Arrow is a child regular match.

Let's look at another example that does not match successfully.

 $url = 'http://www.sina.com.cn/abc/de/fg.php?fff.html?id=1';$matches = array();$pattern = '/(\.){1}[^.|?]+(\?){2}/i';$count = preg_match_all($pattern, $url, $matches);var_dump($count);var_dump($matches);
 

? Output

int 0array (size=3)  0 =>     array (size=0)      empty  1 =>     array (size=0)      empty  2 =>     array (size=0)      empty

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